Agilent Technologies 7820A GC Site Preparation Manual page 16

1 7820A GC Site Preparation
Table 7 Gases usable with Agilent GCs and packed columns (continued)
Detector type
Thermal conductivity (TCD)
* Slightly greater sensitivity than helium. Incompatible with some compounds.
† For analysis of hydrogen or helium. Greatly reduces sensitivity for other compounds.
16
Carrier gas Comments
Helium General use
Hydrogen Maximum sensitivity
Nitrogen Hydrogen detection
Argon Maximum hydrogen
sensitivity
Agilent recommends that carrier and detector gases be
99.9995% pure. See
Agilent also recommends using high quality traps to remove
hydrocarbons, water, and oxygen.
Table 8 Carrier gas purity
Carrier gas requirements
Helium (carrier)
Hydrogen (carrier)
Nitrogen (carrier)
For installation checkout, Agilent requires the gas types shown
in Table 9.
Table 9 Gases required for checkout
Detector Gases required
FID Carrier: helium
Makeup: nitrogen
Fuel: hydrogen
Aux gas: Air
TCD Carrier and reference: helium
NPD Carrier: helium
Makeup: nitrogen
Fuel: hydrogen
Aux gas: Air
uECD Carrier: helium
Anode purge and makeup: nitrogen
*
†
1
Table 8. Air needs to be zero grade or better.
Purity
99.9995%
99.9995%
99.9995%
7820A GC Site Preparation Guide
Detector, anode purge, or
reference
Reference must be same
as carrier and makeup.
Notes
Hydrocarbon free
SFC grade